Fine-tuning of charge transport properties of porphyrin donors for organic solar cell

Abstract

To address the enhancing request of appropriate photovoltaic materials for application in renewable energy resources, an attempt has been made herein to design and investigate the novel porphyrin-based donors with higher transport properties. The interesting furan-linked porphyrin donor (FPD) and thiophene-linked porphyrin donor (TPD) containing Zn metal atom have been previously synthesized and applied into the organic solar cell. Inspired by this fascinating finding, we suggest a new set of porphyrin-based donors with high charge transport properties via designing molecular scaffolds with different numbers of coordinated nitrogen atoms (FPD-Nx and TPD-Nx, x = 0–4) and various types of metal atoms (FPD-M and TPD-M, M = Fe, Co, Ni, Cu, and Zn). Then, the structural, electronic, optical, and charge transport properties of the designed donors have been studied and compared with the available experimental results. Our calculations reveal that the FPD-N2, TPD-N2, FPD-Co, and TPD-Co porphyrins possess the planar structures, proper energy levels in reference to the PCBM acceptor, high open-circuit voltage (VOC), and excellent charge transport properties which make them ideal donors that are used in organic solar cells. Accordingly, our predicted donors represented the improvement in the structural and transport properties which may lead to organic solar cells with high power conversion efficiency. Consequently, this approach can be useful for further improving the efficiency of porphyrin donors in organic solar cells.